I needed to use the saw the cut the mini blind to size to fit into my window frame. I just sawed about a half inch off of either end of the top (mechanism) piece and the bottom piece.
To start off with, I measured the exact opening of the window frame that I wanted the blind to fill. Then I cut and hemmed the fabric into a panel that fit exactly. I left a little excess at the top to be able to wrap around the mechanism piece of the blind. Here is what the fabric looked like:
The next step was to pop off the very bottom piece so that I could take out all of the slats that I didn't need to use. There are two plastic plugs at the bottom that just pop out. Inside you will find a knot. Untie it and you can pull off the bottom piece.
Before you can remove the slats that you don't need, the ladder strings must be cut. These strings hold the slats in the right position. Be very careful not to cut the main cord! It is thicker than the ladder strings.
Once all of the ladder strings are cut off and removed, you are left with all of the slats strung onto the main cord. You can see that they are no longer held into their position and can move around freely. I decided that I wanted my roman blind folds to be about seven inches apart so I made a mark every 7 inches on my painters tape so that it would be easy to line up.
The next step is to remove the slats that you don't need. I positioned my slats at the right distance using my 7 inch marks on the painters tape. Once the slats are removed, reattach the very bottom piece by threading the cord through and retying the knot.
I ended up trimming the ends of each of the slats because they were a bit too wide for the window. I used fabric glue to attach the blind to the fabric. If you use too much glue, it will soak through the fabric so my advice is to put the glue on and then spread it out into a thin layer using a paint brush. The most import part of gluing is to be sure that NO glue touches the cord or your blind will not function. I let the glue dry overnight.
I hung the blind using the usual mini blind hardware that came in the box. Here are some pictures of my new roman blind hanging in the window: